PROJECT SUMMARY/ABSTRACT This is a multi-method, randomized efficacy trial to promote adjustment, co-parenting, and dyadic functioning among expecting couples with heavy drinking fathers and mothers who are light drinking/abstaining during pregnancy. We propose to harness the power of the transition to parenthood as a motivating event providing opportunity for lasting behavioral change. We will examine the efficacy of an innovative prevention strategy (mFF+) that adapts and integrates two evidence-based interventions: 1) Family Foundations (FF) - a universal intervention that has demonstrated meaningful, broad, and durable impacts in universal samples on parent mental health, parenting quality, and couple relations, as well as infant outcomes in multiple trials and 2) brief alcohol intervention (BI) for heavy drinking fathers. This modified intervention (mFF+) is a multi-modal intervention that incorporates alcohol-related content into existing modules of FF and adds a brief intervention for heavy drinking. Expecting couples (n = 180 couples) will be recruited during the first trimester of their pregnancy and randomized into either the mFF+ or control condition. The control condition (CC) will consist of brief advice regarding alcohol use (individualized) and group workshops on community resources and child development taken from Healthy Families intervention, thereby matching the context and delivery of mFF+ and controlling for attention. Existing FF modules will be modified to include alcohol content with discussions around alcohol effects on co-parenting and couple relationship. The adapted mFF+ sessions will be administered in a group format with 5 prenatal classes and 4 postnatal classes. The BI component will be delivered in the original individualized format across three meetings: after the baseline assessment, after the first FF group prenatal session, and approximately 1 month after birth. Our major goal is to examine the efficacy of this modified intervention, mFF+, in reducing fathers' drinking and couple conflict while promoting co-parenting quality, parental sensitivity, and child outcomes among families with heavy drinking fathers. There are two major aims: 1) to conduct a RCT of mFF+ with 180 couples (90 in each condition) with heavy drinking men and light drinking/abstaining women recruited in the first trimester of pregnancy. Parent reports and observational assessments of family functioning will be conducted at baseline (pretest), 6 months postpartum (posttest), and 12 months postpartum (follow-up); 2) to examine whether these impacts on drinking, co- parenting, adjustment, and couple dyadic functioning mediate the impact of mFF+ on parenting, and infant outcomes. This application will advance two major initiatives of the National Institutes of Health: effective intervention for problem alcohol use and prevention of children beginning and continuing to drink alcohol.